In the Arab Gulf countries there are lots of old trucks on the road. I have seen many with Dutch and Polish names and cities still on the doors, but local license plates and making regular deliveries. Trucks engines are designed to last 500k to a million miles, then for about $1500 of parts, they change the cylinder liners, rings, and maybe some bearings, and it can go back into service. In other words, they keep running and running. On the other hand, European countries have ridiculously strict emission standards, and even personal diesel cars like a Mercedes van have a special tank for AdBlue deionized water and urea, and if that tank runs dry, you lose 70% of your power, unless you buy a special box that makes the computer think you have a full load of AdBlue. Thus, old European trucks get sold to countries where the em emissions rules are not so strict, and they have to replace them with new, expensive "clean" trucks.